1. Field of the Invention
The present invention relates to computer convergence devices, and more particularly, but not by way of limitation, to a personal computer/television (PC/TV) convergence device controller for managing the various display geometry and quality characteristics that are available during various operating modes and among various video input sources.
2. Description of Related Art
A computer convergence device is a fully functional computer integrated or converged with another consumer electronic device. One such convergence device is a personal computer/television (PC/TV) convergence device, which integrates a personal computer with television functionality, providing television viewing (via broadcast, cable, Digital Satellite, video cassette recorder (VCR), electronic game device, or other video source) and personal computing functionality. The convergence of a personal computer and television functionality, among other things, permits combined access to television viewing and program information, computer related functionality, and Internet access.
A PC/TV convergence device may comprise a fully function computer including fax/modems, CD-ROM players, and media storage such as hard drives and floppy drives. The convergence with television functionality includes utilizing multiple video inputs to receive a variety of video signals such as from cable systems, VCR, and electronic game machines. The computer is interfaced with a display monitor, often a big screen monitor, with either the interlaced video signal being converted to a scan video graphics adapter (VGA) signal or the computer's scan VGA signal being converted to an National Television Standards Committee (NTSC) interfaced signal. Because the PC/TV convergence device is controlled by the computer's operating system, the PC/TV convergence device can, among other things, simultaneously display PC applications and TV programs on a single monitor. The convergence of personal computer and television functionalities into a single device also permits the utilization of the communications bandwidth, mass storage and graphics of the computer to deliver, store and display small computer applications during a traditional television viewing environment.
In spite of many recent advances in this area, several problems remain. One problem relates the differences between the video geometry settings used to display computer applications and those used to display video applications. The video geometry settings include the physical sizing of the display as well as the display mode (e.g., overscan and underscan modes). Typically, a display for displaying computer applications will require a completely different set of video geometry setting characteristics than a display for displaying television or video applications. In fact, not only are the settings different, but the range of values are often different as well.
Another problem relates to the differences of the video quality characteristics among the various video signals selectable to be displayed on the display monitor. Video quality characteristics include the characteristics that effect the quality of the displayed image, such as the black level, color and contrast of the video signal. For example, computer applications will typically have a lower black level and lower contrast level than a typical VCR video signal. This is because computer applications tend to have more static displays than video applications, and thus by lowering the black level and contrast level display monitor screen burns are prevented. In addition, there are differences in the video quality characteristics between various video signals. Similarly, a video signal received from a cable system source may be at a different level than a VCR video signal or a digital satellite signal.
Accordingly, based upon the foregoing, it should be appreciated that there is a need for a computer convergence control system that is capable of controlling the various display requirements for the various modes of operation of the computer convergence control systems as well as for the varying video signals received by the computer convergence system. That is, it would be advantageous to provide a video controller that can readily control the video geometry and video quality characteristics depending upon the selection of the mode of operation as well as the selection of the video source.